<template>
  <el-breadcrumb class="app-breadcrumb" separator=">">
    <!-- <transition-group name="breadcrumb"> 每次切换菜单会有动画 -->
      <el-breadcrumb-item v-for="(item,index) in levelList" :key="item.path">
        <span v-if="item.redirect === 'noRedirect' || index == levelList.length - 1" class="no-redirect">{{ item.meta.title }}</span>
        <a v-else @click.prevent="handleLink(item)">{{ item.meta.title }}</a>
      </el-breadcrumb-item>
    <!-- </transition-group> -->
  </el-breadcrumb>
</template>

<script setup>
  const route = useRoute()
  const router = useRouter()
  const levelList = ref([])

  function getBreadcrumb() {
    // only show routes with meta.title
    let matched = route.matched.filter(item => item.meta && item.meta.title)
    const first = matched[0]
    // 判断是否为首页
    // if (!isDashboard(first)) { /* 所有页面都会以首页开头 */
    //   matched = [{ path: '/index', meta: { title: '首页' } }].concat(matched)
    // }

    levelList.value = matched.filter(item => item.meta && item.meta.title && item.meta.breadcrumb !== false)
  }
  function isDashboard(route) {
    const name = route && route.name
    if (!name) {
      return false
    }
    return name.trim() === 'Index'
  }
  function handleLink(item) {
    const { redirect, path } = item
    if (redirect) {
      router.push(redirect)
      return
    }
    router.push(path)
  }

  watchEffect(() => {
    // if you go to the redirect page, do not update the breadcrumbs
    if (route.path.startsWith('/redirect/')) {
      return
    }
    getBreadcrumb()
  })
  getBreadcrumb()
</script>

<style lang='scss' scoped>
.app-breadcrumb.el-breadcrumb {
  display: inline-block;
  font-size: 14px;
  line-height: 50px;
  margin-left: 8px;

  .no-redirect {
    color: #97a8be;
    cursor: text;
  }
}
</style>